gnu-efi/gnuefi/crt0-efi-mips64el.S

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/*
* crt0-efi-mips64el.S - PE/COFF header for MIPS64 EFI applications
*
* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
* Copyright (C) 2017 Heiher <r@hev.cc>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice and this list of conditions, without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License as published by the Free Software Foundation;
* either version 2 of the License, or (at your option) any later version.
*/
.section .text.head
/*
* Magic "MZ" signature for PE/COFF
*/
.globl ImageBase
ImageBase:
.ascii "MZ"
.skip 58 // 'MZ' + pad + offset == 64
.4byte pe_header - ImageBase // Offset to the PE header.
pe_header:
.ascii "PE"
.2byte 0
coff_header:
.2byte 0x166 // MIPS little endian
.2byte 2 // nr_sections
.4byte 0 // TimeDateStamp
.4byte 0 // PointerToSymbolTable
.4byte 0 // NumberOfSymbols
.2byte section_table - optional_header // SizeOfOptionalHeader
.2byte 0x206 // Characteristics.
// IMAGE_FILE_DEBUG_STRIPPED |
// IMAGE_FILE_EXECUTABLE_IMAGE |
// IMAGE_FILE_LINE_NUMS_STRIPPED
optional_header:
.2byte 0x20b // PE32+ format
.byte 0x02 // MajorLinkerVersion
.byte 0x14 // MinorLinkerVersion
.4byte _edata - _start // SizeOfCode
.4byte 0 // SizeOfInitializedData
.4byte 0 // SizeOfUninitializedData
.4byte _start - ImageBase // AddressOfEntryPoint
.4byte _start - ImageBase // BaseOfCode
extra_header_fields:
.8byte 0 // ImageBase
.4byte 0x20 // SectionAlignment
.4byte 0x8 // FileAlignment
.2byte 0 // MajorOperatingSystemVersion
.2byte 0 // MinorOperatingSystemVersion
.2byte 0 // MajorImageVersion
.2byte 0 // MinorImageVersion
.2byte 0 // MajorSubsystemVersion
.2byte 0 // MinorSubsystemVersion
.4byte 0 // Win32VersionValue
.4byte _edata - ImageBase // SizeOfImage
// Everything before the kernel image is considered part of the header
.4byte _start - ImageBase // SizeOfHeaders
.4byte 0 // CheckSum
.2byte EFI_SUBSYSTEM // Subsystem
.2byte 0 // DllCharacteristics
.8byte 0 // SizeOfStackReserve
.8byte 0 // SizeOfStackCommit
.8byte 0 // SizeOfHeapReserve
.8byte 0 // SizeOfHeapCommit
.4byte 0 // LoaderFlags
.4byte 0x10 // NumberOfRvaAndSizes
.8byte 0 // ExportTable
.8byte 0 // ImportTable
.8byte 0 // ResourceTable
.8byte 0 // ExceptionTable
.8byte 0 // CertificationTable
.8byte 0 // BaseRelocationTable
.8byte 0 // Debug
.8byte 0 // Architecture
.8byte 0 // Global Ptr
.8byte 0 // TLS Table
.8byte 0 // Load Config Table
.8byte 0 // Bound Import
.8byte 0 // IAT
.8byte 0 // Delay Import Descriptor
.8byte 0 // CLR Runtime Header
.8byte 0 // Reserved, must be zero
// Section table
section_table:
/*
* The EFI application loader requires a relocation section
* because EFI applications must be relocatable. This is a
* dummy section as far as we are concerned.
*/
.ascii ".reloc"
.byte 0
.byte 0 // end of 0 padding of section name
.4byte 0
.4byte 0
.4byte 0 // SizeOfRawData
.4byte 0 // PointerToRawData
.4byte 0 // PointerToRelocations
.4byte 0 // PointerToLineNumbers
.2byte 0 // NumberOfRelocations
.2byte 0 // NumberOfLineNumbers
.4byte 0x42100040 // Characteristics (section flags)
.ascii ".text"
.byte 0
.byte 0
.byte 0 // end of 0 padding of section name
.4byte _edata - _start // VirtualSize
.4byte _start - ImageBase // VirtualAddress
.4byte _edata - _start // SizeOfRawData
.4byte _start - ImageBase // PointerToRawData
.4byte 0 // PointerToRelocations (0 for executables)
.4byte 0 // PointerToLineNumbers (0 for executables)
.2byte 0 // NumberOfRelocations (0 for executables)
.2byte 0 // NumberOfLineNumbers (0 for executables)
.4byte 0xe0500020 // Characteristics (section flags)
.set push
.set noreorder
.align 4
.globl _start
.ent _start
.type _start, @function
_start:
daddiu $sp, -32
sd $ra, ($sp)
// Get pc & gp
.align 3
bal 1f
sd $gp, 8($sp)
_pc:
.dword _gp
.dword _DYNAMIC
.dword _relocate
1:
// pc in ra
ld $gp, ($ra)
dli $t0, _pc
dsubu $gp, $t0
daddu $gp, $ra
sd $a0, 16($sp)
sd $a1, 24($sp)
// a2: ImageHandle
move $a2, $a0
// a3: SystemTable
move $a3, $a1
// a0: ImageBase
dli $t1, ImageBase - _pc
daddu $a0, $ra, $t1
// a1: DynamicSection
ld $t1, 8($ra)
dsubu $t1, $t0
daddu $a1, $ra, $t1
// call _relocate
ld $t1, 16($ra)
dsubu $t1, $t0
daddu $t9, $ra, $t1
jalr $t9
nop
bnez $v0, 1b
nop
// a0: ImageHandle
ld $a0, 16($sp)
Make ELF constructors and destructors work This makes setup and teardown functions defined with __attribute__((__constructor__) and __attribute__((__destructor__)) work in normal circumstances in EFI binaries. A couple of notes: - it implements both the old-style .ctors/.dtors methods and the newer style .init_array/.fini_array ELF constructor and destructor arrays, processed in the order: .init_array[] .ctors[] efi_main() .dtors[] .fini_array[] - Destructors will only be called if efi_main() exits using "return"; any call to Exit() will still longjmp() past them. - InitializeLib() has already been called before constructors run, so they don't need to call it (and neither does anything else.) For compatibility, it has been altered so calling it more than once is safe. - No attempt is made to handle any constructor or destructor with a prototype other than "void func(void);", but note that InitializeLib has been called, so LibImageHandle, ST, BS, and RT are set. - The init_array/ctor/dtor/fini_array lists aren't the using the GNU "CONSTRUCTOR" output section command, so they don't start with a size. - The lists are individually sorted during the link stage via SORT_BY_NAME() in the linker script. - The default (empty) init_array/ctor/dtor/fini_array lists are padded out to 8-byte alignment with ".p2align 3, 0", and each list always has at least one ".long 0" at the end of it (even if it's completely empty). As a result, they can have NULLs that need to be skipped. The sections they're in are mergeable, so the NULLs don't have to be exclusively at the end. - The ia64 and mips64el arches have not been tested. Signed-off-by: Peter Jones <pjones@redhat.com>
2023-03-28 15:28:40 +03:00
// call _start
dla $t9, _entry
jalr $t9
// a1: SystemTable
ld $a1, 24($sp)
1:
ld $gp, 8($sp)
ld $ra, ($sp)
jr $ra
daddiu $sp, 32
.end _start
.set pop
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",%progbits
#endif